Interferon induced with helicase C domain 1 (IFIH1) (IFIH1)

Interferon induced with helicase C domain 1 (IFIH1), also known as Melanoma Differentiation-Associated protein 5 (MDA5), is a critical cytoplasmic pattern recognition receptor that senses long double-stranded RNA (dsRNA) typically associated with viral replication (UniProt Q9BYX4). Upon binding to dsRNA, IFIH1 triggers a signaling cascade through the mitochondrial antiviral-signaling protein (MAVS), leading to the production of type I interferons and proinflammatory cytokines (NCBI Gene ID: 64135). This pathway is essential for the innate immune defense against various RNA viruses, including picornaviruses and coronaviruses. However, dysregulation of IFIH1 is linked to several autoimmune and autoinflammatory conditions. Gain-of-function mutations in the IFIH1 gene are a known cause of Aicardi-Goutières syndrome and Singleton-Merten syndrome, characterized by a chronic interferon signature (Rice et al., 2014). Conversely, anti-MDA5 autoantibodies are specific biomarkers for a severe form of dermatomyositis associated with rapidly progressive interstitial lung disease (Sato et al., 2009). Therapeutic strategies targeting IFIH1 mRNA, such as antisense oligonucleotides or siRNA, are being explored to dampen the overactive immune response in interferonopathies and systemic lupus erythematosus (Funabiki et al., 2014).

Other names

MDA5Melanoma differentiation-associated protein 5RLR-2CADM-140 autoantigenHIH1IDDM19

Targeting IFIH1 mRNA typically involves the use of antisense oligonucleotides (ASOs) or small interfering RNAs (siRNAs) to induce RNase H-mediated degradation or RNA interference, thereby reducing the translation of the MDA5 protein and dampening downstream interferon signaling (Rice et al., 2014; Funabiki et al., 2014).